High-modulus polycarbonate compositions

ABSTRACT

This application discloses improved thermoplastic compositions particularly polycarbonates or polyesters prepared from aromatic dihydroxy compounds, which compositions have been modified with certain stiffening agents, which increase, for example, modulus, tensile strength and hardness, while lowering elongation. The stiffening agents are polar compounds which contain at least one atom selected from the group consisting of halogen, oxygen, nitrogen, and sulfur and wherein said polar compound contains at least two nonbridged rings, each ring containing from four to eight atoms, and wherein said rings are either carbocyclic rings or heterocyclic rings, and wherein said polar compound has in at least 65 percent of the length of its molecule one dimension less than about 5.5 Angstrom units, and wherein said polar compound has a glass transition temperature greater than -50* C.

United States Patent Winston J. Jackson, Jr.; John R. Caldwell, both ofKingsport, Tenn. [21] Appl. No. 696,124

[72] Inventors [22] Filed Jan. 8,1968

[45] Patented Dec. 7, 1971 [73] Assignee Eastman Kodak CompanyRochester, NY.

[54] I-IIGH-MODULUS POLYCARBONATE COMPOSITIONS 13 Claims, No Drawings 52us. Cl 260/24, 260/26, 260/302, 260/304 R, 260/306 R,

260/308 R, 260/31.4 R, 260/3 1.8 XA, 260/324,

260/332 R, 260/334 P, 260/336 R, 260/338 R,

[51] Int. Cl C08q 17/16 [50] Field of Search... 260/26, 33.8, 31.2, 31.8X, 33.4, 860,47 X, 47 C, 649,

[56] References Cited UNITED STATES PATENTS 6/1965 Sears 5/1966 Caldwellet a1.

FOREIGN PATENTS 6/1963 Japan OTHER REFERENCES Schnell, Angevante Chemie,68, p. 633- 640, No. 2, 1956 Christopher et al., Polycarbonates,Reinhold Publihsing Corp., Feb. 6, 1962, Pages 135- 136, 147- 149, and159 relied upon, Call Number TP 156.16

Primary E.raminer Donald E. Czaja Assistant E.raminerM. .l. WelshAttorneys-William T, French and Donald W. Spurrell ABSTRACT: Thisapplication discloses improved thermoplastic compositions particularlypolycarbonates or polyesters prepared from aromatic dihydroxy compounds,which compositions have been modified with certain stiffening agents,which increase, for example, modulus, tensile strength and hardness,while lowering elongation. The stiffening agents are polar compoundswhich contain at least one atom selected from the group consisting ofhalogen, oxygen, nitrogen. and sulfur and wherein said polar compoundcontains at least two nonbridged rings, each ring containing from fourto eight atoms, and wherein said rings are either carbocyclic rings orheterocyclic rings, and wherein said polar compound has in at least 65percent of the length of its molecule one dimension less than about 5.5Angstrom units, and wherein said polar compound has a glass transitiontemperature greater than -50C.

HIGH-MODULUS POLYCARBONATE COMPOSITIONS This application is acontinuation-in-part of our copending application Ser. No. 561,370 filedJune 29, 1966, issued June 4, 1968 as US. Pat. No. 3,386,935 entitledHIGH MODULUS POLYESTER AND POLYCARBONATE COMPOSITIONS, which in turn isa continuation-in-part of our application Ser. No. 445,686 filed Apr. 5,1965, abandoned Apr. 21, I967 entitled POLYMERIC COMPOSITIONS HAVING IN-CREASED STIFFNESS AND TENSILE STRENGTH, now ulmmlonetl. This presentapplication is also a continuation-impart of our copending applicationSer. No. 372,093 filed June 2, I964, abandoned Apr. 2, 1968 entitledHIGH-MQQQLlJg CRYSTALLINE POLYCARBON- ATE FILMS AND FIBERS. Bothapplication Ser. No. 445,686 and Ser. No. 372,093, referred to above arecontinuation-in-part applications of our previous application Ser. No.137,979 filed Sept. 14, 1961, entitled ADDI- TIVES FOR INCREASINGMODULUS OF ELAS- TICITY OF BQLYCARBONATE FILMS, now US. 3.254.047. 2,

This invention relates to an improvement in thermoplastic compositionsprepared from aromatic dihydroxy compounds and more particularly itrelates to polycarbonate or polyester compositions which have beenmodified to increase the modulus elasticity of said compositions.

For certain film applications, including magnetic tape base,photographic film base, and packaging material, relatively stiff filmsare required that is, films with high-tensile modulus. For certain fiberapplications, including various types of fabrics for wearing apparel,drapery material, and upholstery relatively stiff fibers are required,that is fibers with a high tensile or elastic modulus. Likewise, hightensile or elastic modulus is desirable where the thermoplasticcomposition is molded into shaped objects. Although polyesters andpolycarbonates have many properties desirable for such applications theygenerally have relatively low moduli which drastically limits theirutility.

The principal objects of the invention are: to provide new, highlyuseful polyester and polycarbonate compositions which can be transformedinto film, fibers, and shaped objects having high heat-distortiontemperatures, melting points, hardness, and substantially improvedtensile moduli; and to provide a commercially practical process forpreparing such films, fibers, and shaped objects.

These and other objects hereinafter appearing have been achieved in ageneral sense in accordance with the present invention through thediscovery that high modulus is obtained by forming compositions of thepolyesters and polycarbonates modified with certain stiffness improvingadditives which will be referred to as antiplasticizers. Theantiplasticizers increase the modulus, tensile strength, the hardness ofthermoplastic composition and low the elongation whereas a plasticizerdecreases the modulus, tensile strength, and hardness of thethermoplastic composition and increases the elongation. In generalantiplasticizers which have been found to be effective for polyestersand polycarbonates are polar compounds which contain at least one atomselected from the group consisting of halogen, oxygen, nitrogen, andsulfur and wherein said polar compound contains at least two nonbridgedrings, each ring containing from four to eight atoms, and wherein saidrings are either carbocyclic rings or heterocyclic rings, and whereinsaid polar compound has in at least 65 percent of the length of itsmolecule one dimension less than about 5.5-Angstrom units, and whereinsaid polar compound has a glass transition temperature greater than 50C. In general, the increase in modulus of a polyester or polycarbonatecomposition is obtained by providing a homogeneous mixture consisting ofabout 98 to about 50 percent and preferably from about 90 to about 70percent by weight of a polycarbonate or a polyester and from about 2 toabout 50 percent and preferably between about and about 30 percent byweight of the antiplasticizers of this invention. The resultingthermoplastic composition can then be extruded, solvent-cast into afilm, spun into fibers or filaments, or molded into a shaped object.When compared to compositions containing no antiplasticizer according tothis invention, the polyester and polycarbonate,

compositions of this invention have higher moduli and increased tensilestrengths. Surprisingly, higher tear strengths have also been observedin many of the films which were formed from these respective polymers.Normally it is expected that a stiffening agent would lower the tearstrength. Also, the antiplasticizers substantially lower the moldingtemperature of the plastics by lowering the melt viscosities. This isparticularly advantageous as it is dilTicult to injection mold manypolycarbonates and polyesters because of the high temperature requiredto achieve the necessary flow properties in a molding operation.

A more specific disclosure of the types of polycarbonates and polyesterswhich can be modified with antiplasticizers will be disclosed below.However, it will be understood that the examples disclosed are includedmerely for purposes of illustration and are not intended to limit thescope of the invention unless otherwise specifically indicated.

POLYCARBONATES The polycarbonates which are suitable for use in thisinvention are those which have inherent viscosities of at least 0.4 andwhich contain the residue of at least one aromatic dihydroxy compound.Preferably, these polycarbonates are prepared from bisphenols such asthe aliphatic and the cycloaliphatic bisphenols described in Schnell,Angew, Chem., 68, No. 20 (I956), 633-660 and the polycyclic bisphenolsdescribed by Jackson and Caldwell in Ind. Chem. Prod. Res. and Develop.2, 246 (I963).

In addition to containing the residue of at least -diol. aromaticdihydroxy compound, these polycarbonates also may contain the modifyingresidue O-RO of one or more diols wherein R may be alkyl, alicyclic,aryl, or a combination thereof. The diols may be employed as such in themain condensation reaction or first converted to a bischloroformate.Such alkyl diols may be straight or branched and may contain from two to20 carbon atoms. Representative diols include ethylene glycol,2,2-dimethyl-l,3-propanediol, and 1,10- decanediol. Diols containingcyclic groups include 1,4- cyclohexanediol, l,4-cyclohexanedimethanol,2,5-norbornanediol, and p-xylenealpha, alpha'-diol. Other diols aregiven below in the description of bischloroformate reactants.

The polycarbonates from bisphenols may be prepared by adding phosgeneand/or a bischloroformate of a diol, to a cooled, stirred aqueousmixture containing sodium hydroxide, the bisphenol, any modifying diols,a catalyst, and methylene chloride phase.

A bisphenol (residue shown by O-BO) and phosgene give recurringstructural units in the polymer of:

A bisphenol and a bischloroformate of a diol (residue shown by giverecurring structural units of:

The diol from which the bischloroformate is prepared may be aromatic,aliphatic, or alicyclic, and may be primary, secondary, or tertiary. Thecarbon chain of aliphatic diols may be straight, or branched and maycontain from two to 20 carbon atoms. Examples of diols are ethyleneglycol; 1,6-hexanediol; 2,5-norbornanediol; trans-l,4-cyclohexanediol;2,5- dimethyl-2,5-hexanediol; hydroquinone; and4,4'-isopropylidenediphenol. Also any of the following groups may bepresent in the molecule (R alkyl or aryl): R,C--O,

Bischloroformates of aliphatic and alicyclic diols may be prepared byadding an excess of phosgene to the diol suspended in ethylenedichloride. If the diol reacts very slowly, some dry dioxane is alsoadded to increase its solubility in the medium. After all of the diolhas been dissolved, dry air is passed in until all of the hydrogenchloride and excess phosgene has been swept out. The bischloroformatesolution may then be used as needed in the polymerization reactions.

Bischloroformates of aromatic diols, including bisphenols, may beprepared by simultaneously adding the diol (dissolved in dioxane) anddimethylaniline to a stirred solution of phosgene in toluene. A similarprocedure is described in British Pat. No. 613,280.

When a bischloroformate is added to the reaction mixture, the molaramount of the bisphenol preferably should be equal or in slight excessmole percent). When phosgene and a bischloroformate are both added, orthe phosgene alone is used, the phosgene preferably should be 5 to molepercent in excess of its equivalent bisphenol in the reaction mixture. Aquaternary ammonium salt or hydroxide increases the rate ofpolymerization. This may also be accomplished with certain tertiaryamines, such as tri-n-butyl amine, which is preferred. The optimumtemperature range is l5-25 C. At lower temperatures a longer reactiontime is required. At higher temperatures hydrolysis tends to lower theinherent viscosity of the polymer product. Depending upon the catalystused, the normal reaction time required to obtain a maximum molecularweight product may vary from 10 minutes to 2 hours. The reaction rate isslower if impure reactants or if no catalyst is used. Longer reactiontimes permit polymer hydrolysis which tends to lower its molecularweight. At the end of the reaction time the alkali present must beneutralized with acetic, hydrochloric, or other acid.

After the reaction is completed, the polymer layer is diluted by addingmethylene chloride and then is washed thoroughly with water. The polymercan be precipitated by slowly pouring the methylene chloride phase intomethanol, hexane, or other nonsolvent.

In addition to the interfacial process just described for preparing thepolycarbonates of this invention, these polymers may also be prepared byadding phosgene and/or a diol bischloroformate to a stirred mixturecontaining the bisphenol and a tertiary amine, such as pyridine ortriethylamine. A portion of the tertiary amine may be replaced with asolvent for the polymers, such as methylene chloride. in contrast to theinterfacial process, in this process it is not necessary to addnonaromatic diols in the form of their bischloroformates-the diolsthemselves may be added. Copolycarbonates are then obtained whenphosgene is added to the bisphenol/diol mixture in the tertiary amine.

These polycarbonates also may be prepared by the ester interchangeprocess, that is, by heating the bisphenol, a diaryl carbonate, and asuitable catalyst under reduced pressure. Satisfactory diaryl carbonatesinclude diphenyl carbonate, ditolyl carbonate, dixylyl carbonate, anddinitrophenyl carbonate. Catalysts include the oxides, hydrides, andhydroxides of alkali metals and alkaline earth metals and also the freealkali and alkaline earth metals. Other suitable catalysts include butyllithium, phenyl lithium, zinc oxide, lead oxide, dibutyltin oxide, andsodium aluminate. The usual method is followed of heating the reactantsunder reduced pressure to remove the phenolic compound as thecondensation proceeds. Required temperatures are 250350 C. It ispreferred to build up final molecular weight by the solid-phase processin which the granulated polymer is heated under reduced pressure(preferably below 1 mm. of mercury) at a temperature somewhat below itsmelting point.

The polycarbonates of this invention also include copolycarbonatesprepared, for example, by condensing more than one bisphenol with eitherphosgene, a diol bischloroformate or a diary! carbonate, or bycondensing a mixture of a bisphenol and two or more dioldischloroformates. Block copolycarbonates are prepared by condensing amixture of low-molecular-weight 'homopolycarbonates with phosgene. Mixedcopolymers are prepared by condensing a bisphenol with abischloroformate of a polymeric diol (e.g., polyethylene oxidebischloroformate). Further explanation of various polycarbonatepreparations is contained in copending U.S. application, Ser. No.292,139, filed July 1, 1963 now U.S. Pat. No. 3,317,400.

POLYESTERS The polyesters, which are suitable for use in this invention,are those that have relatively rigid chains and are prepared from cyclicintermediates such as the'alicyclic secondary diols and dicarboxylicacids such as the aromatic dicarboxylic acids, the alicyclicdicarboxylic acids, carbonic acid and the esterifiable derivatives ofthese acids.

Polyesters prepared from primary diols do not exhibit the improvedmoduli properties when the antiplasticizers of this invention areblended therewith. Apparently the primary diols give the respectivepolymer too much flexibility and, thus, do not result in a compositionhaving higher moduli when used in accordance with this invention.

The secondary alicyclic diols may be monocyclic or polycyclic and maycontain from four to 14 carbon atoms. Examples are l,3-cyclobutanediol,2,2,4,4-tetramethyl-l,3- cyclobutanediol,2,4-dibutyl-2,4-diethyl-l,3-cyclobutanediol, 1,3-cyclopentanediol,l,3-cyclohexanediol, 1,4-cyclohexanediol, 1,5-cyclooctanediol,2,5-norbornanediol (l), decahydro-l,4:5, 8-dimethanonaphthalene-2,6-diol (ll), dispiro(4'l4-l) dodecane-6, l2-diol (Ill), anddispiro(55-l) tetradecane-7, l4-diol (IV). The latter four polycycliccompounds have the following structures:

OH OH HO-l HO I II HO O H HO H H OH H OH III IV Aromatic dicarboxylicacids used in preparing the polyesters may contain from eight to 16carbon atoms and may contain one or more aromatic rings. Examples areterephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid,4,4'-diphenic acid, 4,4-methylenedibenzoic acid, and4,4'-sulfonyldibenzoic acid.

Alicyclic dicarboxylic acids used in preparing the polyesters maycontain from six to 16 carbon atoms and may be monocyclic or polycyclic.Examples include l,3-cyclobutane-dicarboxylic acid,l,3-cyclopentanedicarboxylic acid,[l,3-]2,5- norbomanedicarboxylic acid,and decahydro-l,4:5, 8- dimethanonaphthalene-2,6-dicarboxylic acid.

It is well known that in the preparation of polyesters the diol may becondensed with derivatives of dicarboxylic acids through the esterinterchange aswell as with the acids themselves. Those compounds whichcan be used in the preparation of polyesters as functionally equivalentsubstitutes for dicarboxylic acids are intended to be included withinthe term, esterifiable derivatives. These derivatives includedicarboxylic acid esters, such as the dimethyl ester of terephthalicacid and the dibutyl ester of 4,4 -sulfonyldibenzoic acid; thedicarboxylic acid halides such as terephthaloyl chloride and 1,3-cyclohexanedicarbonyl chloride; and other suitable substitutes fordicarboxylic acids.

The polyesters of this invention also include copolyesters and blockpolyesters. They may be prepared from more than one diol or dicarboxylicacid. Up to 20 weight percent of the polymer may contain units derivedfrom an aliphatic diol or dicarboxylic acid.

All of thc polyesters of this invention are prepared by conventionalpolyesterification methods. The preparation of one of the most desirablepolyesters for use in this invention is one made from2,2,4,4-tetramethyl-l ,3-cyclobutanediol and is described in a copendingPat. application, Ser. No. 860,375 filed by Elam, Martin, and Gilkeyentitled, LINEAR POLYESTERS AND POLYESTER-AMIDES FROM 2,2,4,4,-TETRAALKYL- 1 ,B-CYCLOBUTANEDIOLS.

ANTIPLASTICIZERS The antiplasticizers which are incorporated into thepolyesters or polycarbonates to produce an increase in strengthproperties and in moduli are materials which, in general, are polar andwhich contain bulky structures with a relatively high degree ofrigidity. These materials may bei polymeric or monomeric and,preferably, are nonvolatile, thus inhibiting migration of theantiplasticizer from the plastic composition. The antiplasticizer must,of course, be compatible with the respective polycarbonate or polyesterpolymer. Antiplasticizers which are soluble to the extent of at least 5percent by weight in methylene chlorine at 20 C. are usually compatiblewith polycarbonates and polyesters. Moreover, a film of the respectivepolymer compositions containing the antiplasticizers is clear andtransparent when the antiplasticizer is compatible with the plastic.

In general, compounds which will serve as antiplasticizer for thepolycarbonate or polyester compositions of this invention are polarcompounds which contain at least one atom selected from the groupconsisting of halogen, oxygen, nitrogen, and sulfur; they contain atleast two nonbridged rings containing V from four to eight atoms whereinsaid rings are either carbocyclic or heterocyclic rings; they have in atleast 65 percent of the length of the molecule one dimension less thanabout 5.5-

Angstrom units, and they have a glass transition temperature greaterthan 50 C.

The antiplasticizers which are useful for the polyesters andpolycarbonates of this invention are all relatively rigid, polarmolecules, considerably less stiffening of the polymer occurs, and thetensile strength is not appreciably increased. For example, when 20percent of biphenyl was added to Bisphenol A polycarbonate the moduluswas increased somewhat to 3.7 l0 p.s.i., but the tensile strength wasdecreased. When 20 percent of biphenyl containing 54 percent chlorinewas added the modulus was increased to 4.5Xl 0 p.s.i. and the breakstrength was increased to 14,200 p.s.i. The effect of the polar groupson the respective compounds is demonstrated by the following data intable I.

Additive was added to 4,4'-isopropylidene diphenol polycarbonate incone. of 20 percent. Similar results were obtained with otherpolycarbonates and polyesters described herein.

In addition to being polar the antiplasticizers must be relatively thinmolecules. The importance of the size in thickness of an antiplasticizeris demonstrated by the phthalate esters. Dimethyl and dibutylphthalates, which contain only one ring, are plasticizers whereasdicyclohexyl and diphenyl phthalates, which are larger molecules withthree rings, have an antiplasticizing effect. Upon inspection of tablell, it is apparent that dicyclohexyl phthalate is less effective as anantiplasticizer than diphenyl phthalate, but cyclohexyl groups areappreciably thicker than phenyl groups (5.1 Angstroms vs. 2.7 Angstromaccording to Fisher-Hirschfelder-Taylor models). According to the filmmodulus, addition of tertiary octyl groups to the para position of thephenyl rings decreased the stiffening effect of the additive. Thethickness of the octyl groups is 6.2 Angstroms. The thick octyl grouphas a greater effect on the modulus when they were at each end of themolecule in the terephthalate diester instead of clustered on one sidein the phthalate. The two octyl groups in the terephthalate constitutehalf the length of the molecule, and a film containing 20 percent ofthis additive had a modulus of compounds. When polar groups are notpresent in the 55 only 3.2Xl0 p.s.i.

TABLE II.-EFFECT OF THICKNESS 0F PHTHALATE ESTERS l Phthalate was addedto 4,4-isopropylidene diphenol polycarbonate in cone. of 20%. Similarresults were obtained with other polycarbonates and polyesters describedherein.

Fisher-Hirschfelder-Taylor models indicated that antiplasticizers areinclusive of compounds wherein at least 65 percent of the length of themolecule had one cross-sectional dimension less than about 5.5 Angstromsand over half of it is less than 5.0-Angstroms thick. However, as shownin table I abietic acid esters are quite effective as antiplasticizers.ln contradistinction, bridged rings structures such as the norbornanederivatives do not show an effective antiplasticizing effect. Althoughsome of the norbornane additives slightly increase the modulus of thefilms, the tensile strength was decreased in every instance. In fact, inmost examples the modulus and the tensile strength was actuallydecreased when a norbornane derivative was used as an additive.Apparently thick molecules such as the norbornane derivatives, whichcontain a norbomane ring having a thickness of 6.5 Angstroms, push thepolymer chain so far apart that the attractive forces between the chainsare appreciably reduced. Consequently, the stiffness and tensilestrength of the polymer are decreased.

The antiplasticizers must also have a relatively high degree ofrigidity. Cyclic structures introduced rigidity into a molecule, andaromatic compounds are generally more effective antiplasticizers thanstaturated alicyclic compounds; aromatic rings are thinner thanalicyclic rings. Molecules containing at least two rings are moreeffective antiplasticizers than molecules containing only one ring. Forexample, dialkyl phthalates are plasticizers as exemplified in tables [Iand 111.

Table Ill Additive was added to 4,4'-isopropylidene diphenolpolycarbonate in conc. of percent. Similar results were L d with otherand a described herein.

It is apparent from table II] that polar groups in themselves will notmake a compound an antiplasticizer but that at least two rings impartthe necessary rigidity to the molecule. The rings may be fused together,as in a phenanthrene nucleus, or

they may be separated from one another as in diphenylsulfone. The ringsmay be carbocyclic or heterocyclic and may contain from four to eightcarbon atoms. To prevent the molecule from being too thick at least twoof the rings must be nonbridged.

Not all thin, polar compounds containing at least two rings areantiplasticizers. Some, in fact, are plasticizers, e.g., dibenzylsuccinate which contains a flexible group between the two phenyl J.Phys. A more quantitative measure of the rigidity of the molecule,therefore, is required.

An indicated of the rigidity of a molecule is given by its glasstransition temperature. This may be determined for quenched,noncrystalline samples by differential thermal analysis, as described inJ. Phys. Chem., 68, 1750 (1964). Quenching of the sample is achieved byheating above the melting point (if a solid) and then quickly cooling inliquid nitrogen. The glass transition temperatures of a number ofadditives are listed in table IV, and it is significant that compoundswith the lowest glass transition temperatures are plasticizers whereasthose with the higher glass transition temperatures areantiplasticizers. The most effective antiplasticizers are the compoundswith transition temperatures above 50 C. The effectiveness of theantiplasticizing action does not increase as the glass transitiontemperature increases, because the polarity and thickness of themolecule become the dominant factors.

Table IV Glass Transition Temperatures of Additives 6 loss transitionAdditive Temperature,

Di-n-octylphthalate Diethylphthalate Di(2-ethylhexyl)phthalateTri(o-crelyl)pho|phate Dibenzyl luccinate Abietic acid, methyl esterDicyclohexyl phthalate Chlorinated biphenyl, 54% Cl Hydrogenated abieticacid,

triethylene glycol ester 28 Diphenyl phthalate IS Poly(styrene glycol),

mol. wt. 500 l() Chlorinated terephenyl, 42% Cl 4 Chlorinatedterephenyl, 6070 Cl 55 In summary, an antiplasticizer for thepolycarbonates and polyesters of this invention (1) contains at leastone polar atom selected from the group consisting of halogen, oxygen,nitrogen, and sulfur, (2) contains at least two nonbridged ringscontaining from four to eight atoms and selected from the groupconsisting of carbocyclic and heterocyclic rings, (3) has in at least 65percent of the length of its molecule one crosssectional dimension lessthan about 5.5-Angstroms units, and (4) has a glass transitiontemperature greater than 50 C.

An especially useful class of antiplasticizer compound are furtherdefined wherein said antiplasticizer (1) contains at least twononbridged rings, each ring containing from five to six carbon atoms,wherein the rings are either carbocyclic rings or N-heterocyclic rings,(2) contains at least one substituent directly bonded to said rings,wherein said substituent contains at least one atom selected from thegroup consisting of oxygen, nitrogen, and sulfur, (3) has in at least 65percent of the length of its molecule one cross-sectional dimension lessthan about 5.5 Angstroms and over half of its molecule is less than 5.0Angstroms thick, wherein these dimensions are determined byFisher-Hirschfelder-Taylor models, and (4) has a glass transitiontemperature of Angstroms than 50 C.

The above examples are only exemplary of the effect of each limitationon the antiplasticizer and are not to be con strued as limiting thescope of the invention. The characteristics of numerous other species ofeach class are set forth in the following tables which furtherdemonstrate the type of compounds encompassed by the specifiedlimitations for effective antiplasticizers.

The preferred classes of compounds which are within the above definitionand have been found to be highly effective as antiplasticizers may begenerally classified as follows:

1. Polystyrene glycol 2. Polystyrene thioglycol 3. Chlorinated aromaticpolynuclear hydrocarbons containing from 30 to 75 percent nuclearchlorine 4. Esters of saturated and unsaturated abietic acid 5. Abietylalcohols, both saturated and unsaturated Polystyrene 6. Esters ofsaturated and unsaturated abietyl alcohols.

Polystyrene glycol is intended to mean the diol of poly- (Phenylethyleneoxide):

HO-(CHCH2O)xH M. 9%. "A, Polystyrene glycols having molecular weightsfrom 378 to 3,000 (x=325) are suitable as additives for increasing themodulus of plastic materials according to this invention.

Polystyrene thioglycol is a polymer from phenylethylene sulfide. it hasthe structure:

Thioglycol suitable for the invention range in molecular weight from 440to 3400 (xii-25).

Chlorinated aromatic polynuclear hydrocarbons containing 30 to 75percent nuclear chlorine are excellent additives as antiplasticizers forpolycarbonates or polyesters. This type is frequently preferred becausethe additive not only increases the modulus, but it may also providefire-retardant properties. Types of aromatic polynuclear hydrocarbonswhich may be chlorinated for this purpose are diphenyl, the terphenyls(o, m, and p), naphthalene, phenanthrene, and anthracene. Also,chlorinated aromatic compounds with the following structures areeffective:

Other antiplasticizers are the diabietates of aliphatic andcycloaliphatic diols containing from two to 20 carbon atoms. Thealiphatic diols from which the diabietates are made may bestriaght-chain or branched. Aromatic or alicyclic groups may be present.Examples of these diols include l,4-butanediols; l,l-decanediols;2,2-dimethylpropanediol; 2,2,4- trimethyl-l ,3-pentanediol;l,4-cyclohexanedimethanol; l,4- alpha, alpha'-xylylenediol;l,4-cyclohexanediol; 2,5-norcamphanediol. Ether linkage may be present,as represented in diethyleneglycol, and tetraethyleneglycol. Polyhydroxycompounds containing from three to carbon atoms can be used, such asglycerol or pentaerythritol. Diabietates may be prepared fromunsaturated abietic acids or from hydrogenated abietic acid. Technicalgrades of abietic acid and rosin acids can be employed in preparing theglycol esters.

Monoesters of abietic or hydrogenated abietic acids and monohydroxyalcohols containing from about one to carbon atoms are also useful asantiplasticizers. Typical alcohols are methanol, 2-ethylhexanol,cyclohexanol, 2-norcamphanol, and benzyl alcohol.

Abietyl alcohol and hydrogenated abietyl alcohol are suitableantiplasticizers for this invention. Hydrogenation of abietic acid andabietyl alcohol reduces the two double bonds in the compounds.

Esters from unsaturated and hydrogenated abietyl alcohols and monoestersesters and diesters obtained from these two alcohols and monocarboxylicand dicarboxylic acids are also suitable antiplasticizers. Many of theseesters are available commercially. Monocarboxylic acids suitable formaking these esters are those containing from about one to 20 carbonatoms. Aliphatic chains in the acids may be straight or branched.Aromatic or alicyclic groups may be present. Examples of the acidsinclude acetic, 2-ethylhexanoic, cyclohexanecarboxylic,2-norcamphanecarboxylic, benzoic, and phenylacetic. Ether linkages maybe present, such as in phenoxyacetic acid. Straight-chain or brancheddicarboxylic acids may be used which contain from about two to 20 carbonatoms. Aromatic or alicyclic groups may be present. Examples of theseacids include adipic, dimethylmalonic, l,4-cyclohexanedicarboxylic,isophthalic, and 2,5-norcamphanedicarboxylic. Ether linkages may bepresent, such as in diglycolic acid.

The preferred antiplasticizers for polycarbonates and polyesters are: (lchlorinated diphenyls and terphenyls comprising from about 30 to 75percent chlorine; (2) poly(styrene-glycols) having a molecular weight ofabout 378 to about 1500; and (3) esters from the condensation ofmonohydroxy and polyhydroxy alcohols with unsaturated and hydrogenatedabietic acids; abietyl alcohol; hydrogenated abietyl alcohol; andmonoesters and diesters from condensation of unsaturated andhydrogenated abietyl alcohols with monocarboxylic and dicarboxylic acidshaving up to 19 carbon atoms.

The amount of antiplasticizer which is added to the polycarbonate or thepolyester in accordance with this invention may be from about 2 to about50 percent, preferably from about l0 to about 30 percent by weight ofthe total composition. Due to the chemical differences between thepolycarbonates and the polyesters, slightly different amounts ofantiplasticizer may be necessary in order to accomplish substantiallythe same increase in strength properties or in the modulus ofelasticity. In many embodiments of this invention it has been foundnecessary to employ slightly more antiplasticizer with a polycarbonatethan with a polyester.

The antiplasticizer is conveniently added to the polymer by adding it tothe polymer dope. The polymer may be dissolved in solvents such as thehalogenated hydrocarbons, e.g., chloroform, methylene chloride, etc. Theantiplasticizer is added to the polymer dope and the resulting mixturemay be used in that form for fabrication into various shaped articles,or alternatively, the dope may be evaporated to form dry polymerparticles, which in turn, may be molded or extruded into various shapedarticles. Films are normally made by conventional solvent-castingtechniques in which the polymer dope is spread on a flat surface, thesolvent is evaporated, and the resulting material is stripped away fromthe surface in the form of a self-supporting film. Fibers areconveniently made by dry-spinning the dope. For example, materials ofthis invention can be converted to fibers by dry spinning through a 30-hole (0.075 mm.) spinneret into a chamber at 60l00 C. followed bydrafting. If the polymer mixture is sufficiently insoluble in convenientsolvent, films and fibers may be fabricated by extruding a dry-blendedmixture of the dry polymer and the antiplasticizer.

An alternative procedure when the polymer is to be meltspun, extruded,or molded is to dissolve the antiplasticizer in a solvent which does notdissolve nor appreciably swell the polymer. The solution ofantiplasticizer is added to particles of the polymer (10 to 20-mesh orsmaller in size) and the solvent is evaporated, leaving theantiplasticizer as a deposit on the polymer particles. Suitable solventswhich will dissolve the antiplasticizers but not the polymers includeacetone, methanol, ethanol, hexane, naptha, and cyclohexane.

Films and fibers maybe oriented by stretching or drafting to enchancetheir properties even beyond those provided by the presence of theantiplasticizers. The polyesters and the polycarbonates may becrystalline or noncrystalline. In many applications, noncrystallinefilms are preferred because they are more transparent, while, on theother hand, crystalline fibers are frequently preferred because afterdrafting and heat-setting, they have higher tenacities and meltingtemperatures than noncrystalline fibers.

The effect of adding the antiplasticizer to the polycarbonates or thepolyesters in accordance with this invention is to increase the tensilemodulus (Young's Modulus), to increase the tensile strength at the breakpoint, to decrease the percent elongation at the break point, and,normally, to decrease the heat-distortion temperature.

In addition to the preferred antiplasticizers mentioned on pages 19-20which are readily available commercially, other antiplasticizers whichillustrate our invention and fall within the above-mentionedantiplasticizer definition are structurally represented below. Thestructural formulas have been illustrated to provide a ready comparisonwith the formula. The respective compounds will hereinafter be referredto in table VI and table Vl( A) by the identifying roman numeraladjacent the formula.

-S O2NCH2- To illustrate the invention, several experiments were carriedout in which various polycarbonates and polyesters were prepared andtreated with many different antiplasticizers in 5 differentconcentration ranges.-The following examples are intended to beillustrative and not to be restrictive in any sense I whatsoever.

l 0 mCH| PJOCH2CHO Br EXAMPLE I m a A number of polycarbonates wereprepared from the reacl tants specified in table V. The polycarbonateswere then In W mixed with various antiplasticizers and an organicsolvent N 02 CHI (methylene chloride) was used to prepare dopes fromwhich CH; films were cast. Films were similarly prepared from the g CHpolycarbonates without additives. Modulus of elasticity in ten- 0 J sion(Young's Modulus, E) of each of the films, with and H; g 20 N 02 withoutadditives, was measured and the results are compared below. V In table Vthe polycarbonates were prepared from the 0H 0H 0H 0H s ecified comonents. The inherent viscosit of the l mer is P P y P y l I alsoitemized. H- CH2 CH2 J Table V o n 1 3 0 Cl OH Bisphenol Polycarbonatcsg Polycarbonate: were prepared from: C 0 w A. 4,4-Isopropylidenediphenol(Bisphcnol A) and I phosgene, I.V. l.0l CH2() (5 CHO B.4,4'-(2-Norbornylidcne )diphenol and phosgene,

C. 4.4'-(Hexapydro-4 7methanoindan-5-thidene)- VII VIII diphenol andphosgene, l.V. 0.87 7

CH Di 4,4-(2 Norbornylidenc)bis(2,6-dichlorophenol) s 40 and phosgene,I.V. L83 E. 4 4'-(2,4,6-Trichloro-a- S 03- methylbenzylidene)diphenoland phosgene, I.V.

f F. Equimolur hydroquinonc and 1,4- acyclohcxanediolbischloroformatc,l.V.086

(Q3 1/ l Ulla 011i 0 IX X 5 0 Table VI lists the various mixtures ofpolycarbonate and ad- Z 0 ditive used for making the film. The number incolumn I identifies the respective polycarbonate having thecorresponding number in table V. In column 2 the additive is identified;N a additives identified by roman numerals are illustrated strucl CH3turally above. In column 3 the weight percent of additive in the mixtureis shown. In column 4 is shown the Modulus of elasticity of a film ofthe polycarbonate-additive mixture, and H3 CH3 in column 5 is shown theElongation at Break.

TABLE VI Break Elong. at Po1y- Wt. Modulus, strength. break, carbonateAdditive percent 10 p.s.i. p.s.i. percent A None 0 3. 0-3.3 9, GOO-9,50020-90 Dibutyl phthalate (plastieizer). 20 3. 0 000 i4 -d0 30 2.5 800 12Dibenzyl sebacate (plasticizer). 30 0. 5 3, 900 128 Dibenzyl succinate(plasticizer) v 30 1. 4 3, 114 Chlorinated biphenyl with 54% chlorine 2O4. 5 14, 200 4 -do 30 4. 7 12, 700 4 Chlorinated biphenyl with 68%chlorine 20 4. 0 11,000 7 do 40 4.4 11,000 3 Chlorinated terphe 10 4. 613, 700 4 do 20 4.6 12,800 4 Poly(styrene glycol) 01 m 20 4. 6 13, 600 4Abietic acid, methyl ester... 20 4. 7 12,700 4 Hydrogenated abieticacid, t g 15 4. 1 12, 900 6 Hydrogenated abietyl acetate. 20 4. 4 13,100 4 Compound I 20 4. 4 I2, 300 5 Compound II 20 4. 4 12,700 5 CompoundIII 20 4. 4 12,000 4 finmnmmd 17 4 a 10 am :4

TABLE Vl-(Jontinucd I Break Elong. at I oiy- Wt. Modulus, strength,break, uarhonato Additive percent 10 p.s.i. p.s. percent Compound V 204. 2 11, 500 Compound VI- 20 4. 3 13,500 4 Compound VII. 20 4.2 9, 70016 Compound VIIL. 20 4. 3 12, 7 5 Compound IX 20 4. 3 13, 200 5 B None.3.7 11,000 15 Chlorinated terphenyl with 42% chlorine 20 4. 0 14, 600 3Chlorinated diphenyl methane with 58% chlorine. 20 5. 1 14, 100 3Poly(styrene glycol) 01 mol. wt. 1500 25 4. 8 13, 100 3 Poly (styrenethioglycol) 01' mol. wt. 440 20 4. 7 12,700 3 Abietic acid, methyl ester20 4. 9 12. 500 3 C None 0 3. 11,200 Chlorinated biphenyl with 42%chlorine. 20 4. 0 12,000 3 Chlorinated biphenyl with 54% chlorine. 5 3.9 11,300 4 .d0 10 4.4 13,000 4 d0 20 4. 0 13,600 4 Chlorinated terphenylwith 42% chlorine 20 4. 8 13,800 4 .d0 40 5.6 12,700 3 Chlorinateddiphenyl ether with 46% chlorine. 20 4. 6 12, 900 3 Poly(styrene g ycol)of mol. wt. 750 20 5. 0 12, 500 3 Abietic acid, methyl ester 20 4. 6 12,700 4 Hydrogenated abietic acid, methyl ester. 20 4. 7 12, 000 3Compound X 20 4. 7 11, 600 3 D None 0 4, 7 14, 000 6 Chlorinatedbiphenyl with 54% chlorine. 5 4. 9 13,000 4 d0 10 5.2 13,700 3 ..do 306.1 14,000 3 Chlorinated terphenyl with 42% chlorine 20 5. 7 13,200 3....d0 50 5.4 10,700 3 Chlorinated naphthalene with 52% chlorine 5. 513, 400 3 Poly(styrene thioglycol) of mol. wt. 1200 5. 6 13, 700 3Hydrogenated ahietic acid, 2,2-dimethyl-1,3-propanedlol ester- 5. 5 13,100 3 E None 0 4. a 12, 200 7 Chlorinated blphenyl with 54% chlorine 205. 2 13,400 3 Chlorinated phenanthrene with 48% chlorine 15 5. 1 12, 0003 Po1y(styrene glycol) oi mol. wt. 100 20 5.1 13,600 3 HydroabietylalcohoL... 30 5. 3 13, 500 3 Abietic acid, glyceryl ester 20 5. 4 13,9003 F None 0 3.6 10,100 8 Chlorinated terphenyl with 32% chlorine. 20 4. 111,400 5 Chlorinated anthracene with 56% chlorin 20 4.6 12,000 4Poly(styrene thioglycol) oi mol. wt. 2000 15 4. 3 11, 000 5 Hydroabietylacetate 20 4. 6 12.200 4 Hydrogenated abietic acid, butyl este 15 4. 512,700 4 Diabietyl adipate 30 5. 0 13, 400 3 The polycarbonate moldingplastics containing an- Table Vll tiplasticizers have increased flexuralmodulus (stiffness), yield strength, break strength, and hardness.Representative com- P l Smr M I 3 e o yelter mg a one s lscosi ypositions were in ection molded and tested according to Stan- AZHLhmmmu'awyclobmnediul (46% dard ASTM Procedures (ASTM D1 708 59T, D7476lT and and diphenyi than: D785 -51 Method A). The data exhibiting theimproved pro- 0.92 pertics for the respective samples as set forth intable VI(A). a 2,2,,4-Telramelhyl-l ,S-cyclobutanediol (60% w V V 4 v nA V trans) and diphenyl carbonate 0.80

C 2,2,4A-Tetrarnethyll ,3-cyclobulanediol (69% trans) and dimethylterephthalute 0.83 EXAMPLE II n 2,4-Dibulyl-2,4-dielhyl-,3-cyclobutancdiol and dimethyi trans-l,4-cyclohcxanedicarboxylate 0.72The polyesters which exhlblt the improved properties when al,4-Cyclohexanediol and simethyl dimethyl 2,5 combined with theantiplasticizers of this invention are the nmbornancdiwbmylaw 1.02relatively rigid polyesters defined above. In table Vll there is F zzz rz tlzzjytl y 0 77 I nap I 1511 an exemplary listing of the startingmaterials for seven G mlpimul's'l nemdembm MM and mm polyester materialswhich can be modified according to this ufllfonyldibcnmm 0.60 invention.

TABLE VI(A) Flexural Yield Break Elong. at Rockwell Wt. modulus,strength, strength, break, hardness Polycarbonate Additive percent 10psi. p.s.i p.s.1. percent L A None 1 5'2 15283 13' 283 g1 11%Chlorinated terphenyl with 42% chlorine.. 0 i

. l ith 0 chlorlne.. 10 3. 5 10, 600 10, 700 69 106 iiltffiiitiffllfl-if? 20 3.6 .000 ,900 54 108 D 30 4. 0 12, 200 9, 400 45 109 D I:it "ii'ob' 13083 5; 182 1 i hen l with 68 chlorine 10 l i ir i i g ig g1f 20 3. 6 12, 800 11, 900 66 111 Hydrogenated abietic acid. trlethyleneglycol ester 15 3. 3 10,000 8 104 B None 0 2. 7 10, 900 10, 35 113Chlorinated terphenyl with 60% chlorine... 20 3. 7 13,300 7 In tableVIII there is a listing of the above polyesters, the antiplasticizerused, the amount of antiplasticizer, and the solvent employed. In eachinstance a polymer dope was prepared by dissolving the polyester in thesolvent and then adding the 6 ASTM D1637 61 and Modern Plastics 34, No.3 (1956), I69. Inherent viscosities were measured in 60/40phenol/tetrachloroethane at a concentration of 0.23 g./l ml.

antiplasticizer. The resulting dope was used to coat a 9-inch by Some ofthe polyesters crystallize readily when films are 18-inch glass plateusing a doctor blade. The solvent was cast or fibers spun. Otherpolyesters do not crystallize under evaporated at room temperature andfilms i to 2 mils in the usual conditions of casting films or spinningfibers but, if thickness were removed and kept at room temperatureoverdesired can be obtained in crystalline form if the solvent is night.The films were then heated in an oven at 100C. for 2 to l 0 evaporatedslowly. This has been accomplished readily if the 3 hours to insureremoval of all solvent. After cooling these solvent consists of at leastone component which boils films were employed to determine the physicalproperties between 100 C. and 250 C. and preferably between l20 C. shownin the tabIe VIII. Tensile modulus, tensile strength, and and 180 C.Examples of such solvents are chlorobenzene, oelongation were measuredin accordance with ASTM D882 dichlorobenzene, anisole, cyclohexanone andacetophenone. -6lT Method A. The heat-distortion temperature (2 percentThe two component solvents are used for some of the examdistortion at 50p.s.i.) was measured in accordance with pies in table VIII.

Elon- Antiplasticizer Tensile Tensile gation Heat modulus, strength atdistortion Wt. X10: break, break, Temp Polyester Name percent Solventp.s.i. p.s.i percent C,

A None. 0 CHCh 2.1 6,800 13 133 A- Chlorinated biphenyi (54% Cl) CHCl;4. 6 8, 400 3 A Chlorinated terphenyl (42% Cl) 10 CHCl; 4. 1 10, Z10 387 A .do 10 4:1 anon/camel 4. 5 8, 300 2 108 A .....do 20 4:1CHCla/CaHsOCHa 5.2 7,300 2 147 A do CHzClz 5.4 9,800 3 49 Abietic acid,methyl ester.. 20 CHzClz 4. 1 5, 800 3 111 Sucrose acetate isobutyrate-20 CHgClg 3. 2 7,100 4 76 B None 0 CHCI; 2.9 8,000 8 225 Chlorinatedterphenyl (42% 01).. 20 CHCl; 5. 5 9, 800 2 125 Chlorinated terphenyiCl) 20 CHCl; 4. 3 10, 300 3 Sucrose acetate isobutyrate- 20 CH0]; 3. 08, 100 4 Poiy(styrene glycol) of moi. wt. 500 15 CHCia 3. 8 8, 400 4Hyldroglenated abietie acid, triethyoene 15 5:1 CIiClQ/CAHBCOCHQ 4. 4 7,900 3 172 g YCO CS 81. Abietyl alcohol 20 CIICI; 4. 0 i), 400 4 C None 04:1 CHCla/CFgCOOII 2.2 8,300 15 206 Chlorinated biphenyl (54% Cl) 20 4:1 CHCh/C F COOH 3. 9 10,200 3 88 Chlorinated terphenyi (42% Cl)... 204:1 CHCla/CFaCOOI-I 3. J 10, 700 3 Chlorinated terphenyi (60% Cl) 20 4:1CHCl3/CF3CO0H 3.8 10, 500 3 121 .do 20 4:1 CHClg/CFgCOOH CsHiOCHa 4.59,700 2 150 Chlorinated anthracene (56% 01)-- 10 4:1 CHC13/CF3000H 3. 29, 400 5 Abietic acid, methyl ester 20 4: 1 CHCl3/CF5COOH 3. 9 10, 300 4107 Poly(styrene glycol) of mol. wt. 1500 20 8:21CHCla/CFgCOOH/O-CQILC]; 3.8 9, 200 3 162 D None .l': 0 01101, 2.0 0,90020 Chlorinated biphenyl (54% Cl). 20 CHC]; 3.8 8,800 3 Chlorinatedterphenyi (42% 01).... 2O CHO]; 4.1 9,000 3 Chlorinated phenanthrene(48% 01).. 15 CHCl; 3. 7 7, 800 3 Hydroabietyl acetate 20 CHCia 3. 58,000 4 E None 0 4:1CHC13/CF COOH 2.5 7,200 17 Chlorinated biphenyi (32%01).. 25 4:1 CHCls/CFaCOOlI 3.6 8, 400 4 Chlorinated biphenyl (68% Cl).20 4:1 CHCh/CFaCOOH 4.0 8, 900 3 Chlorinated naphthalene (57% Cl) 10 4:1CHClg/CFgCOOII 3. 3 8, 000 4 Diabletyl adipate. 20 4: 1 CIICl/aCFaCOOII4. 1 8, 800 3 Abietic acid, glyceryl ester 16 4:1 CIICla/C FQCOOH 3. 99, 000 3 Glucose acetate propionate 20 4: 1 CIIClii/CFQCOOII 3. 8 8, 4003 F None 0 4:1 CHClg/CFgCOOII 3.1 8,400 15 Chlorinated terphenyl (54%Cl). 20 4:1 CIIC fl/CFQCOOH 4. 3 10, 700 3 Chlorinated diphenyl ether(46% 15 4:1 CI'IClJ/CFECOOII 4.0 9, 900 3 Hydrogenated abietyl acetate 041 CHCIa/C aCOO 4. 2 10, 200 3 Po1y(5tyrene tioglycol) of mol. Wt. 400-0 411 C C aIC aC 4. 1 700 3 G None 0 CHC/h 2.4 6,400 19 Chlorinatedbiphenyi (54% Cl) l5 CHCI; 3. 6 8, 700 3 Chlorinated diphenyimethane(58% C 10 CHCI; 3.2 7,800 4 Poiy(styrene glycol) of mol. wt. 750 15CHCI; 3.0 7,600 4 Hydrogenated abietic acid, butyi ester. 10 CHCI; 3. 07, 500 4 Hydrogenated abietic acid 2, 2-dlmethyl- 20 CHCl: 3. 7 8, 600 31, 3-propanediol ester. Sucrose acetate propionate 0 CHC s 3. 4 8, 3Compound X 0 C 0]; 3. 5 8, 800 3 F Compound IX 0 411 CHCIa/ FA 4. 3 10,900 3 I) Compound VII. 0 CHCla 2. 8 7, 400 8 Compound VIII. 20 01210133. 9 8, 700 3 C Compound VI 0 4:1 CHCls/TFA 4. 6 9,800 3 B Compound VI20 CHC 3 4.4 9,300 3 Compound III. 20 CHCl; 4. 3 8, 800 Compound V. 20CHCl'; 4. 2 8, 700 Compound VIII 0 C CIa 4. 2 8, 700

A. Compound I 20 CHzClz 4.6 8,100 3 Compound II 0 CHzC 2 4. 5 7, 900 3Tests were performed on polyester molding plastics containingantiplasticizers in accordance with this invention. in

3. A thermoplastic composition according to claim 1 wherein thestiffness improving additive is abietyl alcohol.

4. A thermoplastic composition according to claim 1 table 1X the variousproperties are shown, indicating the inwherein the stiffness improvingadditive is hydrogenated creases in property values obtained whenantiplasticizers were abietyl alcohol. employed. The properties in table1X were determined on in- 5. A thermoplastlc composition according toclaim 1 jection-molded polymers ac ording to tanda d ASTM wherein thestiffness improving additive is an ester from the procedures (ASTM D1708-59T, D747 -6lT, and D785 51 condensation of unsaturated abietylalcohol.

TABLE IX Antiplasticizer Flexural E modulus, Yield Break tion atRockwell Wt. X10- strength, strength, break, hardness Polyester Namepercent p.s.i. p.s.i. p.s percent L A None 2 2% 53 Ch] tedter hen l 4 C-....%f.f ."i.... .ffi"'i m 3.1 8,700 8 101 Chlorinated terphenyl (60%Cl) 30 3. 4 8, 900 7 93 Chlorinated biphenyl (68% Cl) 5 2. 5 6, 600 6,400 47 93 Hydrogenated abietic acid, triethylene glycol ester 10 3. 06,000 5 97 I1 None 0 2. 6 6, 900 6, 500 30 80 Chlorinated terphenyl (42%Cl) 5 2 8,000 7, 500 99 Chlorinated biphenyl (54% Cl) i0 6. 6 8,800 5103 C None 0 2.1 6,600 5 101 Chlorinated terphenyl (42% Cl). 4.0 12,8007 120 Method A). The antiplasticizers, dissolved in acetone orcyclohexane, were deposited on 10 to 20-mesh polyester parthereof, butit will be understood that variations and modifications can be efi'ectedwithin the spirit and scope of this invention as described here andabove and as defined in the appended claims.

We claim:

1. A thermoplastic composition comprising from about 98 to about 50percent by weight of a thermoplastic polymer selected from the groupconsisting of polycarbonates containing the residue of at least onearomatic dihydroxy compound, and from about 2 to about 50 percent byweight of a stiffness improving additive selected from the groupconsisting of polystyrene thioglycols having molecular weights from 440to 3,400, abietyl alcohol, hydrogenated abietyl alcohol, and mono anddiesters from the condensation of unsaturated and hydrogenated abietylalcohols with monocarboxylic and dicarboxylic acids having up to 19carbon atoms.

2. A thermoplastic composition according to claim 1 wherein thestiffness improving additive is a polystyrene thioglycol having amolecular weight from 440 to 3400.

wherein the bisphenol phosgene- 11. A thermoplastic compositionaccording to claim 7 wherein the bisphenol polycarbonate is derived from4,4-( 2- Norbomylidene)bis(2,6-dichlorophenol) and phosgene.

12. A thermoplastic composition according to claim 7 .wherein thebisphenol polycarbonate is derived from hydroquinone and1,4-cyclohexanediol bischloroformate.

13. A thermoplastic composition consisting essentially of from 70 topercent of a bisphenol polycarbonate and 30 to 10 percent of a stiffnessimproving additive selected from the group consisting of abietyl alcoholand hydrogenated abietyl alcohol.

PO-1050 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent3,625,877 Dated December 7, 1971 Inventods) Winston J. Jackson, Jr. andJohn R. Caldwell It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

[ Column 1, line 52, "low" should be -lower. Column 2, line 31, delete"-diol"; line 76, "-R C- -0--, should be --R C, --0, Column L, line 2,"dischloroformates" should be -bischloroformates-; line 3A, "dispiroUr-l l-l)" should be dis'piro( llr- 'l)-; and dis'piro(5- 5- l)" shouldbe -dis'piro(5- l- 5- l). Column 6, Table I, under Modulus for2,2Dinitrobi'phenyl IA" should be "All". Column 7,, line 62, "J. Phys.should be "rings"; line 6%, "indicated" should be --indication. Column8, Table IV, last Additive "Chlorinated terephenyl, 6070 Cl" should beChlorinated terephenyl,

60% Cl-; line L9, "Angstroms" should be greater---; line 67, delete"Polystyrene". Column 9, line 36, "striaght" should be --straig;ht--5line 59, after "monoesters" delete "esters". Column ll, Formula V,

0H 0H OH on i u H -@-CH @011 should be l i I I C H Cl C H Cl 0H 0H 0HFormula VII, CH CH H 3 I @80 0 should be CH CH TEC 10261 P(%-/%%5)0UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 33 5577 D d December 7, lnvmods) Winston J. Jackson, Jr. and John R. CaldwellIt is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

PAGE z FF ormula IX,

. should be CH3OT%W CH3O- CH3 H3 CH3 Column I L, Table VII, the "0.92"under Polyester should be value for Polyester A under InherentViscosity"; Table VII, under "Starting Materials" for Polyester 0, "2,2I II-Tetramethy'll,3-cyclobutanediol. should read --2,2 L,L-Tetramethyl-l,3cyclobutanediol-5 Table VII, under 'Starting Materials"for Polyester E, after "and" delete simethy'l". Columns 15 and 16, TableVIII under "Antiplasticizer" sixth value for Polyester B, 'triethyoene"should be triethylene--; Table VIII, under "Antiplasticizer" fourthvalue for Polyester E, (57% Cl)" should be -(52% Cl)-; Table VIII, under"Anti'plasticizer" last value for Polyester F, "Poly(styrenetioglyco'l)" should be -Poly(styrene thioglyCO1)". Column 2, line 31after "least" insert one Column 8 line 49, cancel "of".

Signed and sealed this 6th day of June 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents TEC 10261

2. A thermoplastic composition according to claim 1 wherein thestiffness improving additive is a polystyrene thioglycol having amolecular weight from 440 to
 3400. 3. A thermoplastic compositionaccording to claim 1 wherein the stiffness improving additive is abietylalcohol.
 4. A thermoplastic composition according to claim 1 wherein thestiffness improving additive is hydrogenated abietyl alcohol.
 5. Athermoplastic composition according to claim 1 wherein the stiffnessimproving additive is an ester from the condensation of unsaturatedabietyl alcohol.
 6. A thermoplastic composition according to claim 1wherein the stiffness improving additive is an ester from thecondensation of hydrogenated abietyl alcohol.
 7. A thermoplasticcomposition according to claim 1 wherein the thermoplastic polymer is abisphenol polycarbonate.
 8. A thermoplastic composition according toclaim 7 wherein the bisphenol polycarbonate is derived from4,4''-isopropylidenediphenol and phosgene.
 9. A thermoplasticcomposition according to claim 7 wherein the bisphenol polycarbonate isderived from 4,4''-(2-Norbonylidene)diphenol and phosgene.
 10. Athermoplastic composition according to claim 7 wherein the bisphenolpolycarbonate is derived from4,4''-(Hexahydro-4,7-methanoindan-5-ylidene)diphenol and phosgene.
 11. Athermoplastic composition according to claim 7 wherein the bisphenolpolycarbonate is derived from4,4''-(2-Norbornylidene)bis(2,6-dichlorophenol) and phosgene.
 12. Athermoplastic composition according to claim 7 wherein the bisphenolpolycarbonate is derived from hydroquinone and 1,4-cyclohexanediolbischloroformate.
 13. A thermoplastic composition consisting essentiallyof from 70 to 90 percent of a bisphenol polycarbonate and 30 to 10percent of a stiffness improving additive selected from the groupconsisting of abietyl alcohol and hydrogenated abietyl alcohol.